# CVE-2026-5367: Ovn: ovn: information disclosure via crafted dhcpv6 packets

> Remote attackers can send crafted DHCPv6 packets to trigger an out-of-bounds read in OVN, disclosing sensitive heap memory contents.

- **Severity:** High 8.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Apr 2026
- **Updated:** 25 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-5367, GHSA-r8vj-9qgr-m84x, UBUNTU-CVE-2026-5367

## What is CVE-2026-5367?

CVE-2026-5367 is a high-severity vulnerability in Red Hat Fast Datapath for RHEL 8, published on 24 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw was found in OVN (Open Virtual Network). A remote attacker, by sending crafted DHCPv6 (Dynamic Host Configuration Protocol for IPv6) SOLICIT packets with an inflated Client ID length, could cause the ovn-controller to read beyond the bounds of a packet. This out-of-bounds read can lead to the disclosure of sensitive information stored in heap memory, which is then returned to the attacker's virtual machine port.

Weakness: CWE-130 (Improper Handling of Length Parameter Inconsistency)

## Which versions are affected by CVE-2026-5367?


## How do I fix CVE-2026-5367?

Apply the vendor's patch.

## Is CVE-2026-5367 being exploited?

There is no known exploitation of CVE-2026-5367 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-5367 and fix it if it is affected.

What it is: CVE-2026-5367 is a high-severity vulnerability in Red Hat Fast Datapath for RHEL 8, published on 24 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-5367 in the wild and no public exploit code.

Affected product: Red Hat Fast Datapath for RHEL 8. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-5367/ (Markdown: https://insights.sbomify.com/CVE-2026-5367/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5367
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5367
- OSV: https://osv.dev/vulnerability/CVE-2026-5367

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-5367/
Summaries are generated and may contain mistakes; the official description above is the record.